This section provides background information related to the present disclosure which is not necessarily prior art.
In recent years, a great deal of emphasis has been directed to development of pedestrian protection systems for use in motor vehicles in an effort to reduce the likelihood or severity of injuries caused during a collision between a pedestrian and a motor vehicle. One such area of development has been directed to equipping the motor vehicle with a hood assembly capable of absorbing impact forces.
A “passive” pedestrian protection system associated with the hood assembly includes providing a pocket of under-hood crush space between the hood and the components within the vehicle's engine compartment. This crush space is configured to reduce the chance of bodily impact with the components within the engine component and, more particularly, to provide an impact absorbing feature. However, the use of low profile hoods in modern motor vehicles for improved aesthetics and aerodynamics, in combination with smaller engine compartments, limits the available crush space.
As an alternative, an “active” pedestrian protection system associated with the vehicle's hood assembly provides a “deployable” hood that is configured to raise a rear portion of the latched hood to create the additional under-hood crush space. This deployable hood feature is activated in response to detection of a pedestrian collision with the front end of the motor vehicle. Typically, a pair of active hinges are incorporated into the hood assembly. Each active hinge includes a pivot linkage interconnecting the hood to the vehicle body and an actuator that is operable to forcibly move the pivot linkage for causing the hood to move from a non-deployed position to a deployed position in response to detection of the pedestrian impact. Examples of active hinges that provide this functionality are disclosed in commonly-owned U.S. Pat. No. 8,544,590 and U.S. Publication No. 2014/0182962.
In some active hinges, the actuator is used to hold the hood in its deployed position. For example, some active hinges use a pyrotechnic actuator which typically requires controlled venting to maintain the upward force that is applied to the pivot linkage. To this end, a need exists to provide alternative solutions for locating and retaining the hood in its deployed position which address and overcome shortcomings of conventional active hinges.